Unusual hyphal branching

we have observed unusual hyphal branching within the host of Acremonium
lolii (an endophyte of ryegrass) isolates which show variant growth
forms when grown in culture. This frequent branching, with odd
pertuberances is not observed in the parental strain which gave rise to
these variants.
Has anyone observed a change in any plant/fungus interaction where the
fungal hyphae are either branching more than normal or they show odd
pertuberances.
thankyou,
Rich.